Sleep fragmentation during rapid eye movement sleep and hypertension in obstructive sleep apnea

Objective: Sleep fragmentation determined by repetitivearousals from sleep in obstructive sleep apnea (OSA) isassociated with hypertension. We aimed to quantify theindependent association of arousals during rapid eyemovement (REM)/non-rapid eye movement (NREM) sleepwith prevalent hypertension. Methods: We included adults with 4h of total sleep timeand at least 30 min of REM sleep obtained from overnightin-laboratory polysomnography. Logistic regression modelswere fitted to explore the association between arousalsduring REM/NREM sleep and prevalent hypertension. Allmodels controlled for OSA metrics and arousals duringNREM/REM sleep, either by statistical adjustment or bystratification. Results: The sample comprised of 11 643 patients, ofwhich 10 055 were OSA patients. Fully adjusted modelsdemonstrated significant dose-relationships betweenarousal index during REM sleep (AI-REM) and prevalenthypertension (Ptrend = 0.002). The higher relative odds ofprevalent hypertension were most evident with AI-REM > 40events/h. In OSA patients with arousal index duringNREM sleep (AI-NREM)< 15events/h, every10-unit increasein the AI-REM was associated with 18% higher odds ofhypertension (odds ratio, 1.18; 95% confidence interval,1.11-1.27) in OSA. On the contrary, AI-NREM was not asignificant predictor of hypertension in any of the models. Conclusions:Our findings indicate that arousals duringREM sleep are associated with prevalent hypertension. Thisis clinically relevant because treatment of OSA is oftenlimited to the first half of the sleep period leaving most ofsleep fragmentation during REM sleep untreated. Graphical abstract: http://links.lww.com/HJH/C126